U.S. patent number 9,464,559 [Application Number 15/015,299] was granted by the patent office on 2016-10-11 for passive exhaust valve assembly and forming method.
This patent grant is currently assigned to MIDDLEVILLE TOOL & DIE CO.. The grantee listed for this patent is Middleville Tool & Die Co.. Invention is credited to Robert Leroy Middleton, Jr., Justin Tyler Middleton.
United States Patent |
9,464,559 |
Middleton, Jr. , et
al. |
October 11, 2016 |
**Please see images for:
( Certificate of Correction ) ** |
Passive exhaust valve assembly and forming method
Abstract
A passive valve assembly for an engine exhaust system includes
an exhaust conduit for transferring exhaust gases from the engine
and a valve plate that is operably disposed within the exhaust
conduit. A pivot rod has an internal section that is coupled with
the valve plate, such that the valve plate may pivot between an
open position and a closed position. The pivot rod also has an
external section that protrudes from the exhaust conduit. A stop
feature is disposed at or near an exterior surface of the exhaust
conduit in a location arranged to contact the external section of
the pivot rod and prevent the valve plate from pivoting beyond one
of the open position and the closed position.
Inventors: |
Middleton, Jr.; Robert Leroy
(Middleville, MI), Middleton; Justin Tyler (Middleville,
MI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Middleville Tool & Die Co. |
Middleville |
MI |
US |
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Assignee: |
MIDDLEVILLE TOOL & DIE CO.
(Middleville, MI)
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Family
ID: |
56552923 |
Appl.
No.: |
15/015,299 |
Filed: |
February 4, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160222863 A1 |
Aug 4, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62111696 |
Feb 4, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01N
1/165 (20130101); F01N 1/166 (20130101); F01N
13/08 (20130101); F02D 9/06 (20130101); F16K
1/22 (20130101); F16K 15/033 (20130101); Y10T
137/7898 (20150401); Y10T 137/7876 (20150401) |
Current International
Class: |
F01N
13/08 (20100101); F16K 1/22 (20060101); F01N
1/16 (20060101); F16K 15/03 (20060101) |
Field of
Search: |
;251/286,288,303,304,305,313 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Robert Leroy Middleton Jr., Justin Tyler Middleton, and Robert
Leroy Middleton Sr., Passive Exhaust Valve with Floating Spring
Stop, U.S. Appl. No. 15/045,565, filed Feb. 17, 2016. cited by
applicant .
International Search Report and Written Opinion dated Apr. 14, 2016
from corresponding PCT Application No. PCT/US2016/016502. cited by
applicant.
|
Primary Examiner: Schneider; Craig
Assistant Examiner: Soski; Frederick D
Attorney, Agent or Firm: Gardner, Linn, Burkhart &
Flory, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims benefit under 35 U.S.C. .sctn.119(e)
of U.S. Provisional Application Ser. No. 62/111,696, entitled
PASSIVE EXHAUST VALVE ASSEMBLY AND FORMING METHOD, filed Feb. 4,
2015, which is hereby incorporated herein by reference in its
entirety.
Claims
What is claimed is:
1. A passive exhaust valve assembly, comprising: a conduit for
transporting exhaust gases; a pivot rod extending through a wall of
the conduit to define an internal section and an external section
of the pivot rod; a valve plate disposed in the conduit and coupled
with the internal section of the pivot rod, the pivot rod rotatable
to move the valve plate between open and closed positions; and a
cover member disposed at a wall of the conduit to substantially
conceal an aperture in the wall of the conduit, wherein the cover
member comprises a flange protruding outward from the conduit, and
wherein the flange comprises a stop feature arranged to contact the
external section of the pivot rod when the valve plate pivots
toward at least one of the open and closed positions to prevent
further rotation of the pivot rod beyond the respective open or
closed position.
2. The passive exhaust valve assembly of claim 1, wherein the stop
feature is configured to resiliently flex upon contact with the
pivot rod as the valve plate moves toward the open or closed
position, thereby effectively reducing noise.
3. The passive exhaust valve assembly of claim 1, wherein the pivot
rod spans across an internal volume of the conduit and pivotally
engages an opposing wall of the conduit.
4. The passive exhaust valve assembly of claim 1, wherein the stop
feature of the flange includes a tab portion angled relative to the
wall of the conduit.
5. The passive exhaust valve assembly of claim 4, wherein the stop
feature is an integral portion of the cover member.
6. The passive exhaust valve assembly of claim 4, wherein the cover
member includes a spring anchor adapted for engaging a tension
spring that spans between the cover member and the external section
of the pivot rod and biases the valve plate in the closed
position.
7. The passive exhaust valve assembly of claim 1, wherein the
flange of the cover member includes a spring anchor, and wherein
the spring anchor is adapted for engaging a tension spring that
attaches between the cover member and the external section of the
pivot rod for biasing the valve plate in the closed position.
8. A passive valve assembly for an engine exhaust system, said
passive valve assembly comprising: an exhaust conduit for
transferring exhaust gases from the engine; a valve plate operably
disposed within the exhaust conduit and pivotable between an open
position and a closed position; a pivot rod having an internal
section coupled with the valve plate and an external section
protruding from the exhaust conduit; and a stop feature disposed at
or near an exterior surface of the exhaust conduit and having a tab
portion angled relative to the exterior surface of the exhaust
conduit, wherein the tab portion is arranged to contact the
external section of the pivot rod and prevent the valve plate from
pivoting beyond one of the open position and the closed position,
and wherein the tab portion is configured to resiliently flex
relative to the exhaust conduit upon initial contact with the
external section of the pivot rod as the valve plate is pivoting
toward the open position or the closed position.
9. The passive exhaust valve assembly of claim 8, wherein the tab
portion is an integral piece of a cover member attached at the
exterior surface of the exhaust conduit and spanning over an
aperture in a sidewall of the exhaust conduit.
10. The passive exhaust valve assembly of claim 8, further
comprising: a spring coupled between the external section of the
pivot rod and the exhaust conduit to bias the valve plate in the
closed position.
11. The passive exhaust valve assembly of claim 8, wherein the
pivot rod is coupled with a pair of bushings disposed at opposing
walls of the exhaust conduit.
12. The passive exhaust valve assembly of claim 8, wherein the
external section of the pivot rod includes an end portion that is
angled from a rotational axis of the internal section to contact
the stop feature and thereby reduce noise associated with the valve
plate moving to the open or closed position.
13. The passive exhaust valve assembly of claim 8, further
comprising: a cover member coupled with the exhaust conduit about
an aperture in a sidewall of the exhaust conduit to substantially
conceal the aperture, the cover member having a curved shape
substantially aligned with a curvature of the exhaust conduit.
14. The passive exhaust valve assembly of claim 13, wherein the
stop feature is disposed at the cover member and protrudes away
from the exhaust conduit, and wherein the valve plate is disposed
at or near a concave side of the cover member.
15. The passive exhaust valve assembly of claim 13, wherein the
exhaust conduit includes a pair of axle supports for engaging
bushings on opposing sides of the exhaust conduit, and wherein the
pivot rod rotatably engages the bushings.
16. A method of forming a passive exhaust valve, comprising:
providing a first circumferential portion of a tubular conduit
having a saddle area disposed on at least one lateral edge of the
first circumferential portion; engaging a pivot rod at the saddle
area to locate a valve plate in an interior of the tubular conduit,
wherein the valve plate is coupled with an internal section of the
pivot rod, such that rotation of the pivot rod moves the valve
plate between open and closed positions; aligning a second
circumferential portion with the lateral edges of the first
circumferential portion to form the tubular conduit around the
valve plate; welding the first and second circumferential portions
together; wherein the second circumferential portion includes a
cover member that is sized to substantially conceal an aperture in
a wall of the second circumferential portion to form the tubular
conduit; and wherein the cover member includes a flange that
protrudes outward to form a stop feature arranged to contact an
external section of the pivot rod and prevent rotation of the pivot
rod when the valve plate assumes one of the open position and the
closed position.
17. The method of claim 16, wherein the cover member includes a
stop feature that is arranged to contact an external section of the
pivot rod when the valve plate pivots toward at least one of the
open position and the closed position to prevent further rotation
of the pivot rod beyond the respective open or closed position.
18. The method of claim 16, wherein the cover member includes a
spring anchor for attaching a tension spring that spans between the
spring anchor and the external section of the pivot rod, whereby
the tension spring biases the valve plate in a closed position.
19. The method of claim 16, further comprising: engaging a bushing
between the saddle area and the pivot rod for rotatably supporting
the pivot rod.
20. The method of claim 16, wherein an external section of the
pivot rod includes an end portion that is angled from a rotational
axis of the internal section, the end portion configured to contact
the stop feature when the valve plate moves toward the open or
closed position.
21. A passive exhaust valve assembly for an engine exhaust system,
said passive valve assembly comprising: an exhaust conduit for
transporting exhaust gases; a valve plate operably disposed within
the exhaust conduit and pivotable between an open position and a
closed position; a pivot rod engaging an axle support at least
partially disposed at a wall of the exhaust conduit, wherein the
pivot rod includes an internal section coupled with the valve plate
and an external section protruding from the exhaust conduit; a
spring anchor disposed at or near an exterior portion of the
exhaust conduit for engaging a spring that extends to the external
section of the pivot rod to bias the valve plate in the closed
position; a stop feature disposed at or near the exterior portion
of the exhaust conduit and arranged to contact the external section
of the pivot rod when the valve plate pivots toward at least one of
the open and closed positions to limit rotation of the pivot rod;
and a cover member attached at the wall of the exhaust conduit to
substantially conceal an aperture in the wall of the conduit,
wherein the cover member includes an integral flange having a
portion protruding from the wall of the exhaust conduit and
comprising at least one of the stop feature, the spring anchor, and
a portion of the axle support.
22. The passive exhaust valve assembly of claim 21, wherein the
pivot rod is coupled with a bushing disposed at the axle support on
the exhaust conduit.
23. The passive exhaust valve assembly of claim 21, wherein the
external section of the pivot rod includes an end portion that is
angled from a rotational axis of the internal section, and wherein
the end portion is arranged to contact the stop feature.
24. The passive exhaust valve assembly of claim 21, wherein the
cover member includes a curved shape substantially aligned with a
curvature of the wall of exhaust conduit.
25. The passive exhaust valve assembly of claim 21, wherein the
stop feature is disposed at the integral flange of the cover
member.
26. The passive exhaust valve assembly of claim 21, wherein the
integral flange of the cover member includes the stop feature and
the spring anchor.
27. The passive exhaust valve assembly of claim 21, wherein the
axle support is provided at a seam between the cover member and the
wall of the exhaust conduit.
28. The passive exhaust valve assembly of claim 21, wherein the
exhaust conduit includes a pair of axle supports that engage
bushings on opposing sides of the exhaust conduit, and wherein the
pivot rod rotatably engages the bushings.
Description
FIELD OF THE INVENTION
The present invention relates generally to the field of passive
exhaust valves, and more particularly to components and features
that assist in moving and biasing a vane or valve plate of a
passive valve assembly in an exhaust conduit and corresponding
methods of forming and installing such a valve assembly in an
exhaust conduit.
BACKGROUND OF THE INVENTION
To control back flow pressure and reduce low frequency engine noise
in exhaust systems of combustion engines, it is generally
understood that a passive valve may be provided in the exhaust line
to alter characteristics of exhaust flow by actuating in response
to changes in exhaust pressure. Passive valves may regulate exhaust
pressure and attenuate exhaust system noise; however, in some
instances they can also create undesired noises, such as noises of
a valve plate closing against an interior surface of a valve
conduit, and squeaking or fluttering noises of the valve plate
moving between open and closed positions, for example when
experiencing exhaust pressure fluctuations or pulses. In addition
to providing undesirable acoustics for the exhaust system, these
noises may cause pre-mature wear and damage to the valve and other
negative consequences to performance of the exhaust system.
Further, passive valve assemblies can be difficult to install and
assemble in a cost effective manner.
SUMMARY OF THE PRESENT INVENTION
The present invention provides an exhaust conduit or pipe section
that includes a valve plate or vane member that can pivot within
the interior volume or flow path of the exhaust conduit to regulate
the flow of exhaust gases through the exhaust conduit, such that
noises that can be generated by movement of the valve plate may be
reduced or eliminated. In accordance with one aspect of the present
invention, a passive exhaust valve includes a conduit for
transporting exhaust gases and a pivot rod that extends through a
wall of the conduit to define a internal section and an external
section of the pivot rod. A valve plate is disposed in the conduit
and is coupled with the internal section of the pivot rod, whereby
the pivot rod is rotatable to move the valve plate between open and
closed positions. A stop feature is coupled with the conduit and
arranged to contact the external section of the pivot rod when the
valve plate pivots toward at least one of the open and closed
positions to prevent further rotation of the pivot rod beyond the
respective open or closed position.
In accordance with another aspect of the present invention, a
passive valve assembly for an engine exhaust system includes an
exhaust conduit for transferring exhaust gases from the engine and
a valve plate that is operably disposed within the exhaust conduit
and is pivotable between an open position and a closed position. A
pivot rod has an internal section that is coupled with the valve
plate and has an external section that protrudes from the exhaust
conduit. A stop feature is disposed at or near an exterior surface
of the exhaust conduit in a location arranged to contact the
external section of the pivot rod and prevent the valve plate from
pivoting beyond one of the open position and the closed
position.
Optionally, a cover member may be coupled with the conduit or
exhaust conduit to substantially conceal an aperture in the wall or
sidewall of the conduit at or near the intersection with the pivot
rod. The cover member may have a curved shape that substantially
aligns with a curvature of the conduit. Also, the stop feature may
optionally be an integral portion or piece of the cover member.
In accordance with yet another aspect of the present invention, a
method of forming a passive exhaust valve includes providing a
tubular conduit having an aperture in a sidewall of the tubular
conduit. A valve plate is inserted through the aperture into the
tubular conduit and a pivot rod engages at opposing sides of the
tubular conduit, where an intermediate section of the pivot rod is
coupled with the valve plate for rotation of the pivot rod to move
the valve plate between open and closed positions. A cover member
is attached about the aperture to substantially conceal the
aperture.
In accordance with yet another aspect of the present invention, a
method of forming a passive exhaust valve includes providing a
first circumferential portion of a tubular conduit having a saddle
area disposed on at least one lateral edge of the first
circumferential portion. A pivot rod is engaged at the saddle area
to locate a valve plate in an interior of the tubular conduit. The
valve plate is coupled or preassembled with an internal section of
the pivot rod, such that rotation of the pivot rod moves the valve
plate between open and closed positions. A second circumferential
portion is aligned with the lateral edges of the first
circumferential portion to form the tubular conduit around the
valve plate, and then the first and second circumferential portions
are welded together.
These and other objects, advantages, purposes and features of the
present invention will become apparent upon review of the following
specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an upper perspective view of a passive exhaust valve
assembly, according to one embodiment of the present invention;
FIG. 2 is another upper perspective view of the exhaust valve
assembly shown in FIG. 1, taken from an opposite end from that
shown in FIG. 1;
FIG. 3 is a top plan view of the exhaust valve assembly shown in
FIG. 1;
FIG. 4 is an end elevation view of the exhaust valve assembly shown
in FIG. 1, having a valve plate in a closed position;
FIG. 5 is an exploded perspective view the exhaust valve assembly
shown in FIG. 1;
FIG. 6 is a side elevation view of the exhaust valve assembly shown
in FIG. 1, having the valve plate in the closed position;
FIG. 6A is an enlarged cross-sectional view of a stop feature of
the exhaust valve assembly, taken at line VIA-VIA of FIG. 3;
FIG. 7 is a side elevation view of the exhaust valve assembly shown
in FIG. 1, having the valve plate in an open position;
FIG. 7A is an enlarged cross-sectional view of the stop feature of
the exhaust valve assembly, taken at line VIA-VIA of FIG. 3,
showing the valve plate in the open position;
FIG. 8 is an upper perspective view of a cover member of the
exhaust valve assembly, having one embodiment of a stop
feature;
FIG. 8A is a top perspective view of an additional embodiment of a
cover member of the exhaust valve assembly, having another
embodiment of a stop feature;
FIG. 8B is a top perspective view of an additional embodiment of a
cover member of the exhaust valve assembly, having another
embodiment of a stop feature;
FIG. 8C is a top perspective view of an additional embodiment of a
cover member of the exhaust valve assembly, having yet another
embodiment of a stop feature;
FIGS. 9A-9D illustrate successive steps of forming of a conduit
with a sidewall aperture for an exhaust valve assembly, according
to one exemplary embodiment; and
FIGS. 10A-10F illustrate successive steps of installing or
assembling an exhaust valve within the exhaust conduit shown in
FIG. 9D, according to one exemplary embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring to the drawings and the illustrative embodiments depicted
therein, reference numeral 10 generally designates a passive valve
assembly that includes an exhaust conduit 12 for transporting
exhaust gases. A valve plate 14 is operably coupled within an
internal volume of the exhaust conduit 12 and is configured to
pivot between an open position 16 and a closed position 18 that
reduces flow of the exhaust gases through the exhaust conduit 12. A
pivot rod 20 has a first section 22 coupled with the valve plate 14
and a second section 24 external to the exhaust conduit 12 and
angled relative to the first section 22. A stop feature 26 is
coupled with the exhaust conduit 12 proximate the pivot rod 20 and
has a protrusion 28 that abuts the second section 24 of the pivot
rod 20 with the valve plate 14 in the open position 16 and/or the
closed position 18. The stop feature 26 is configured to reduce
noise by preventing impact of the valve plate 14 against an
interior surface of the exhaust conduit 12.
With reference to FIGS. 1 and 2, the exhaust conduit 12 of the
passive exhaust valve assembly 10 includes a tubular shape having
an inlet end 30 and an outlet end 32 on opposing ends of the
exhaust conduit 12 to respectively receive and transfer exhaust
gases longitudinally though the exhaust conduit 12. A conduit axis
of the exhaust conduit 12 extends centrally through the internal
volume of the exhaust conduit 12 between the inlet and outlet ends
30, 32. The valve plate 14 is positioned within the internal volume
and is pivotal between the open position 16 and the closed position
18 for preventing exhaust gases from transferring through the
tubular conduit. Although shown as a tubular shape, it is
conceivable that the exhaust conduit 12 in additional embodiments
may have a different cross-sectional shape and may not be linear in
the longitudinal direction.
As further illustrated in FIGS. 1 and 2, an upper portion of the
tubular conduit includes a cover member 34, which may also be
referred to as a hood piece, which is attached around an aperture
36 in a sidewall of the exhaust conduit 12. The cover member 34
substantially conceals the aperture and has a curved shape between
opposing lateral sides of the cover member 34 that substantially
aligns with a curvature of the tubular conduit. It is, however,
contemplated that the upper section or circumferential portion of
the tubular conduit may be removed or omitted to form an aperture
that spans the length of the conduit, such that the cover member
would fill the open circumferential portion to enclose or surround
the assembled valve plate.
The opposing lateral sides of the cover member 34 in the
illustrated embodiment are provided with upper embossed
indentations 38 or saddle areas, such as shown in FIG. 1, with a
rounded interior surface configured to contain and support the
pivot rod 20. The upper embossed indentations 38 on the cover
member 34 are aligned and mated with corresponding lower embossed
indentations 40 or saddle areas on the sidewall of the exhaust
conduit 12, formed on edges of the aperture 36. The upper and lower
embossed indentations 38, 40 together form a pair of axle supports
42 on opposing sides of the exhaust conduit 12 for supporting and
rotatably engaging the pivot rod 20. In the illustrated embodiment,
the axle supports 42 may include bushings 44 that engage directly
between the pivot rod 20 and the upper and lower embossed
indentations 38, 40 for reducing friction and noise from the
rotation of the pivot rod 20. The bushings 44 may include a metal
wire mesh, a solid sleeve, or a combination of materials to provide
a relatively low friction surface for rotation of the pivot rod 20.
With respect to materials, the bushings 44 may include one or a
combination of metal alloys, such as bronze and iron, ceramics, and
composite materials, such as those containing carbon fibers and
polymers. In additional embodiments, it is contemplated that the
axle supports 42 may not include bushings or that the bushings may
be integrally formed with the axle supports 42. It is also
conceivable that the embossed indentations in other embodiments may
be differently shaped and configured to be contained on more or
less of the cover member 34 or the sidewall of the exhaust conduit
12.
Referring now to FIGS. 3 and 4, the pivot rod 20 of the depicted
embodiment has an internal section 22, or first section, that
extends laterally through the exhaust conduit 12 to couple with the
valve plate 14 and the axle supports 42. An external section 24, or
second section, of the pivot rod 20 is show angling perpendicularly
from one end of the internal section 22 of the pivot rod 20 and
extending adjacent to the exterior surface of the exhaust conduit
12. A distal end portion 46 of the external section 24 angles
perpendicularly in parallel alignment with the internal section 22
to define a spring attachment point. A tension spring 48 is thereby
secured to the spring attachment point, which includes radial
protrusions from the distal end portion 46 on opposing sides of the
spring to prevent the spring from sliding laterally and disengaging
from the spring attachment point on the spring arm. The external
section 24 of the pivot rod 20 is thereby shown to have an L-shape
formed with the distal end portion 46. It is contemplated, however,
that the external section 24 of the pivot rod 20 may be
alternatively shaped or angled, such as to provide a contact
surface for the stop feature and/or a spring attachment point for
attaching a tension spring.
As shown in FIG. 3, an opposing end of the tension spring 48 is
attached at a spring anchor 50 that is fixed relative to the
exhaust conduit 12, such that the tension spring 48 biases the
external section 24 of the pivot rod 20 against the stop feature
26. The stop feature 26 protrudes outward from the exterior surface
of the exhaust conduit 12 and is configured to abut the external
section 24 of the pivot rod 20, defining the closed position 18 of
the valve plate 14. The external section 24 of the pivot rod 20 is
spring-biased against the stop feature 26 with the tension spring
48, thereby biasing the valve plate 14 in the closed position 18 in
the embodiment shown in FIG. 3, which is described in greater
detail herein.
Still referring to FIGS. 3 and 4, the internal section 22 of the
pivot rod 20 spans across the internal volume of the exhaust
conduit 12 in an orientation substantially orthogonal relative to
the conduit axis and offset above the conduit axis. Opposing ends
of the internal section 22 are pivotally coupled with the axle
supports 42 on opposing sidewalls of the tubular conduit to provide
rotational movement of pivot rod 20. An intermediate portion of the
pivot rod 20, between the opposing ends of the internal section 22
is rigidly coupled with the valve plate 14, such that rotation of
the pivot rod 20 operates the valve plate 14 between the open and
closed positions 16, 18. The valve plate 14 thereby is pivotally
coupled with a concave side of the cover member 34.
The illustrated embodiment of the valve plate 14, as shown in FIG.
4, includes upper and lower arcuate edges 52, 54 that substantially
conform to the interior surface proximate the valve plate 14, which
is defined by the curved shape of the cover member 34 and the
curvature of the exhaust conduit 12, respectively. Between the
arcuate edges 52, 54, the valve plate 14 includes linear edges
substantially orthogonal to the internal section 22 of the pivot
rod 20. Clearance areas are defined between the exhaust conduit 12
and the linear edges of the valve plate 14 to allow the valve plate
14 to pivot about the pivot rod 20 between the open and closed
positions 16, 18. However, it is conceivable that the clearance
areas may be eliminated or reduced by altering the shape of the
exhaust conduit 12 proximate the valve plate 14 to conform the
interior surface to the linear edges.
As depicted in FIGS. 4 and 5, the valve plate 14 in the illustrated
embodiment, proximate the upper arcuate edge 52 is provided with an
attachment configuration for rigidly engaging the intermediate
portion of the pivot rod 20. The illustrated embodiment of the
attachment feature includes alternating curved bends in the valve
plate 14 that each engage a side of the pivot rod 20. A central
curved bend is provided with an aperture to weld or otherwise
fixedly engage the pivot rod 20, such that valve plate 14 rotates
in unison with rotation of the pivot rod 20. It is conceivable that
the valve plate 14 or the pivot rod 20 in additional embodiments
may have different attachment configurations or designs to provide
a rigid connection between an upper portion of the valve plate 14
and the intermediate portion of the pivot rod 20.
With continued reference to the embodiment shown in FIGS. 4 and 5,
the cover member 34 has a peripheral flange 56 that engages the
edge of the aperture 36 in the sidewall of the exhaust conduit 12,
which substantially conceals the aperture 36. As shown, a second
flange 58 protrudes from the peripheral flange 56 on one lateral
side of the cover member 34 proximate the external section 24 of
the pivot rod 20. The stop feature 26 is disposed on a first end of
the flange 58 and the spring anchor 50 disposed on an opposing
second end of the flange 58. The spring anchor 50 is formed by
rolling the second end of the flange 58. The stop feature 26
includes a tab that angles rearward to abut the external section 24
of the pivot rod 20 with the valve plate 14 in the closed position
18. As such, the stop feature 26 in the depicted embodiment is an
integral piece of the cover member 34. A longitudinal extent of the
tab spans from a first location adjacent to a pivotal axis of the
internal section 22 of the pivot rod 20 to a second location
adjacent to the external section 24 of the pivot rod 20. The tab is
configured to abut the external section 24 of the pivot along the
longitudinal extent of the tab for reducing noise associated with
the valve plate 14 moving to the closed position 18.
Additional embodiments of the stop feature 26 are illustrated in
FIGS. 8-8C. In the embodiment shown in FIG. 8, the tab of the stop
feature 26 includes an indented channel, also referred to as a
bead, which is configured to increase the surface area of the tab
that contacts the pivot rod 20. Specifically, the indented channel
includes a curved surface that substantially corresponds with the
exterior surface of the external section 24 of the pivot rod 20.
Also, in the embodiment shown in FIG. 8A, the tab 126 has a
substantially planar upper surface for abutting the pivot rod 20.
Moreover, in the embodiment shown in FIG. 8B, the tab 226 is
elongated and the secondary flange 58 proximate the tab is bent
downward to align the upper edge of the tab 226 with an exterior
surface of the internal section 22 of the pivot rod 20, thereby
further increasing the surface are of the tab 226 that contacts the
pivot rod 20 in the closed position 18. Further, in the embodiment
shown in FIG. 8C, the tab 326 is has an upper portion arranged to
contact the pivot rod 20 when the valve plate pivots toward one or
both of the open and closed positions to prevent further rotation
of the pivot rod beyond the respective open or closed position. In
the embodiments, the stop feature may be configured to resiliently
flex upon contact with the pivot rod as the valve plate moves
toward the open or closed position, thereby effectively absorbing
impact energy and reducing associated noise. It is contemplated
that additional embodiments of the tab may include bead forms for
strengthening and increasing rigidity of the stop feature, and
further other embodiments of the stop feature may have additional
protruding elements and may be formed with a multitude of different
shapes and configurations for abutting the pivot rod to control the
positioning of the valve plate.
Referring now to FIGS. 6 and 6A, the tension spring 48 includes a
coiled portion between the ends thereof that are coupled with the
spring anchor 50 on the cover member 34 and the spring attachment
point on the external portion of the pivot rod 20. As depicted in
FIGS. 6 and 6A, the tension spring 48 has the valve plate 14 biased
is in the closed position 18, such that the tension spring 48
extends in substantially parallel alignment with the center axis of
the exhaust conduit 12. The valve plate 14 in the illustrated
embodiment has a dimension between the upper and lower arcuate
edges 52, 54 that is greater than the inside diameter of the
exhaust conduit 12, such that the valve plate 14 is oriented an
angle less than 90 degrees in the closed position 18. This
orientation of the valve plate 14 prohibits it from rotating beyond
the point at which the upper and/or lower arcuate edges 52, 54 abut
the interior surface of the exhaust conduit 12. However, in the
illustrated embodiment of the closed position 18, the upper and
lower arcuate edges 52, 54 of the valve plate 14 are spaced from
the interior surface of the exhaust conduit 12. This spacing is
maintained by the stop feature 26 abutting the external section 24
of the pivot rod 20. The spacing also reduces clanking noise that
may be generated by abutment between the valve plate 14 and the
interior surface of the exhaust conduit 12.
With reference to FIGS. 7 and 7A, when exhaust pressure from the
inlet end 30 of the exhaust conduit 12 is sufficient to overcome
the biasing force of the tension spring 48, the external section 24
of the pivot rod 20 rotates away from the stop feature 26 and
pivots the valve plate 14 in the internal volume toward the open
position 16. The biasing force of the tension spring 48 may
increase as the valve plate 14 opens and the tension spring 48
stretches. The exhaust pressure from the inlet end 30 of the
exhaust conduit 12 may likewise be released as the valve plate 14
opens. As such, in operation, it is contemplated that the passive
valve assembly may be coupled with a muffler having a through pipe
coupled with the outlet end 32 of the exhaust conduit 12 and a
passage extending to at least one muffler chamber upstream from the
inlet opening. In such an arrangement, with the valve plate 14 in
the closed position 18 (FIGS. 6 and 6A), the exhaust gases will be
restricted from passing through the valve assembly and urged to
enter the at least one muffler chamber before exiting the muffler.
When the exhaust pressure exceeds a threshold corresponding with
the biasing force of the tension spring 48, the valve plate 14 may
pivot to the open position 16 to release the pressure by allowing
the exhaust to exit the muffler via the through pipe, avoiding the
at least one muffler chamber.
The method of forming a passive exhaust valve according to one
embodiment is generally illustrated in a series of steps shown
FIGS. 9A-10F. Initially, to provide the exhaust conduit 12, with
the aperture 36 in the sidewall and the lower embossed indentations
40 of the previously illustrated embodiment, some exemplary forming
steps are shown in FIGS. 9A-9D. At the step shown in FIG. 9A, a
sheet material 60 is provided that has cutouts stamped on opposing
edges of the sheet. It is contemplated that the cutouts may
alternatively be combined and stamped centrally on the sheet 60 to
form the aperture 36. To form a tubular-shaped exhaust conduit 12
with the stamped sheet material 60, as shown in FIG. 9B, the sheet
material 60 is formed around a cylinder shape to substantially
engage the opposing edges in abutting contact. To assist with
maintaining the cylindrical shape of the exhaust conduit 12, a
central mandrel may be used where the cylindrical shape is shown in
dashed lines in FIG. 9B. In another embodiment, the tubular shape
of the exhaust conduit may also be done by roll forming the sheet
material 60 or by other known processing to form a section of
exhaust pipe. As shown in FIG. 9C, the opposing edges are attached,
such as by welding, a lock seam, and other means, with the cutouts
aligned to define an aperture 36 in a sidewall of the tubular
conduit. Again, in another embodiment, the cutouts may be combined
and stamped in a central portion of the sheet material 60 to avoid
alignment issues. It is also conceivable that in additional
embodiments, tubular conduit may be formed without stampings or
cutout sections as a standard piece of pipe cut to length, and then
the aperture may be cut or otherwise punched from the sidewall of
the tubular conduit, with known means for exhaust pipe cutting and
trimming.
To form the lower embossed indentations 40 in the opposing lateral
edges of the aperture 36, a support structure may be formed around
the exhaust conduit 12, as shown in FIG. 9C, whereby a cradle 62,
or external mandrel, may engage the exterior surface of the exhaust
conduit 12. A press or cam action inserts or the like may be urged
against the opposing lateral edges of the aperture to form the
lower embossed indentations 40 of the axle supports 42. Upon
forming the lower embossed indentations 40, the blank 64 and cradle
62 may be removed as shown in FIG. 9D. It is contemplated that the
lower embossed indentations in other embodiments may be formed
prior to or simultaneously with the sheet material being formed in
the tubular shape, such as shown in FIGS. 9A and 9B. The steps
illustrated in FIGS. 9A-9D may be done in a different sequence from
that illustrated and may be accomplished with alternative methods
of stamping, cutting, forming, and joining, as generally understood
by one having ordinary skill in the art.
Referring now to the assembly steps of the method of forming a
passive exhaust valve shown in FIGS. 10A-10F, the exhaust conduit
12 is provided with the sidewall aperture 36 and the lower embossed
indentations 40. The pivot rod 20 is also provided with bushings
44, which may be press fit or otherwise secured to the pivot rod
20, and the valve plate 14 fixedly coupled with the internal or
intermediate portion of the pivot rod 20. As shown in FIG. 10A, the
pivot rod 20 and valve plate 14 are together aligned above the
sidewall aperture 36 of the exhaust conduit 12. The valve plate 14
is then inserted at an angle into the internal volume of the
exhaust conduit 12, as shown in FIG. 10B. The pivot rod 20 is then
engaged with the lower embossed indentations 40, as shown in FIG.
10C, whereby the bushings 44 are seated in the lower embossed
indentations 40 or saddle areas. The cover member 34 is then
provided, as shown in FIGS. 10D and 10E, and joined at the
periphery of the cover member 34 around the aperture 36 to conceal
the aperture 36 and engage the upper embossed indentations 38 with
the lower embossed indentations 40 to form the axle supports 42.
Further, as shown in FIG. 10F, the method includes attaching a
tension spring 48 between the spring anchor 50 on the flange 58 and
an external section 24 of the pivot rod 20, whereby the tension
spring 48 biases the valve plate 14 in a closed position 18. Again,
it is conceivable that these steps may be done in a different
sequence from that illustrated and may be accomplished with
alternative methods of attaching, assembling, stamping, cutting,
forming, and joining, as generally understood by one having
ordinary skill in the art.
The disclosure has been described in an illustrative manner, and it
is to be understood that the terminology which has been used is
intended to be in the nature of words of description rather than of
limitation. Many modifications and variations of the present
disclosure are possible in light of the above teachings, and the
disclosure may be practiced otherwise than as specifically
described.
It will be understood by one having ordinary skill in the art that
the specific devices and processes illustrated in the attached
drawings and described in this specification are simply exemplary
embodiments of the inventive concepts defined in the appended
claims. Hence, specific dimensions and other physical
characteristics relating to the embodiments disclosed herein are
not to be considered as limiting, unless the claims expressly state
otherwise. It will also be understood that construction of the
described invention and other components is not limited to any
specific material. Other exemplary embodiments of the invention
disclosed herein may be formed from a wide variety of materials,
unless described otherwise herein.
For purposes of this disclosure, the terms "upper," "lower,"
"right," "left," "rear," "front," "vertical," "horizontal," and
derivatives thereof shall relate to the invention as oriented in
FIG. 1. However, it is to be understood that the invention may
assume various alternative orientations, except where expressly
specified to the contrary. Also, for purposes of this disclosure,
the term "coupled" (in all of its forms, couple, coupling, coupled,
etc.) generally means the joining of two components (electrical or
mechanical) directly or indirectly to one another. Such joining may
be stationary in nature or movable in nature; may be achieved with
the two components (electrical or mechanical) and any additional
intermediate members being integrally formed as a single unitary
body with one another or with the two components; and may be
permanent in nature or may be removable or releasable in nature,
unless otherwise stated.
Changes and modifications in the specifically-described embodiments
may be carried out without departing from the principles of the
present invention, which is intended to be limited only by the
scope of the appended claims as interpreted according to the
principles of patent law including the doctrine of equivalents.
* * * * *